1. Field of the Invention
The present invention relates to an image forming apparatus. More particularly, the present invention relates to an image forming apparatus including a switchgear that facilitates the smooth engagement of gears without damaging the gears when a developer is inserted in a body of the image forming apparatus.
2. Description of the Related Art
Generally, an electrophotographic image forming apparatus prints an image by forming an electrostatic latent image on a photosensitive drum or a photosensitive belt and developing the electrostatic latent image using a predetermined type of toner. Such an electrophotographic image forming apparatus is typically classified as a dry electrophotographic image forming apparatus or a liquid electrophotographic image forming apparatus according to the toner used.
The liquid electrophotographic image forming apparatus uses ink containing a liquid carrier and solid toner at a predetermined ratio. The liquid electrophotographic image forming apparatus forms an image having superior print quality more easily, compared with the dry electrophotograhic image forming apparatus.
The electrophotographic image forming apparatus can also be classified into an adhesive transfer image forming apparatus or an electrostatic transfer image forming apparatus according to how a toner image is transferred.
In the adhesive transfer image forming apparatus, after a toner image is dried, the dried toner image is heated, pressed, and transferred onto a sheet of print paper by a transfer roller. The electrostatic transfer image forming apparatus transfers a toner image onto a sheet of print paper using an electrostatic force.
A removable developer, which stores toner and forms an electrostatic latent image, is installed in such an electrophotographic image forming apparatus. Thus, when the toner in the developer runs out, the developer is replaced with a new developer storing new toner to form an image. When the developer is installed in a body of the electrophotographic image forming apparatus, power can be transmitted as gears are engaged with each other.
FIGS. 1 and 2 are schematic side views of a conventional image forming apparatus illustrating the transmission of power when the developer is installed in a body of a conventional image forming apparatus. Referring to FIG. 1, a main motor 30 and a photosensitive medium driving gear 31 are installed on a side frame (not shown) of the body. The photosensitive medium driving gear 31 receives power from the main motor 30 through meshing between the teeth of the main motor 30 and the teeth of the photosensitive medium driving gear 31, thereby driving a photosensitive medium (not shown).
In the upper part of the side frame of the main body, a developing roller driving motor 10 and an idle gear 22, which is rotated by power transmitted from the developing roller driving motor 10, are installed. Also, a swing gear 23 is rotatably installed in a bracket 21, which is engaged with the idle gear 22 to be rotatable about the idle gear 22 as a rotation axis. The bracket 21 elastically rotates by being connected to an elastic unit 24.
A developer 40 includes a developing roller (not shown) and a photosensitive medium (not shown). A developing roller gear 41 transmitting power to the developing roller and a photosensitive medium gear 42 transmitting power to the photosensitive medium are installed to protrude from the developer 40.
When the developer 40 is pushed in a direction indicated by the arrow in FIG. 1 and inserted into the body, the developing roller gear 41 engages with the swing gear 23. Accordingly, the photosensitive medium gear 42 engages with the photosensitive medium driving gear 31. When the developing roller driving motor 10 rotates, power is sequentially transmitted to the idle gear 22, the swing gear 23, and the developing roller gear 41. When the main motor 30 rotates, power is sequentially transmitted to the photosensitive medium driving gear 31 and the photosensitive medium gear 42.
Conversely, when the developer 40 is removed from the body, the swing gear 23 is rotated in reverse to release the swing gear 23 from its engagement with the developing roller gear 41. Since the swing gear 23 is engaged with the developing roller driving motor 10 through the idle gear 22, an additional load is imposed on the swing gear 23 by the developing roller driving motor 10, thereby making it difficult for the developer 40 to be removed from the body. If the developer 40 is forcibly removed from the body, gears that are engaged with the developer 40 may be damaged.
Accordingly, a need exists for an improved image forming apparatus having an easily removable developer that substantially eliminates damage to the gears upon removal.